<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="https://unpkg.com/vue/dist/vue.js"></script>
</head>
<body>
<div id="app">
  <select v-model="selected" name="fruit">
      <option value="0">o</option>
      <option value="1">一</option>
      <option value="2">二</option>
      <option value="3">三</option>
  </select>
    <div id="output">
        选择的网站是:{{selected}}
    </div>
</div>
</body>
<script>
    new Vue({
        el: '#app',
        data: {
            selected: '2'
        }
    })
</script>
</html>